I would like to have the javadoc comments contained in a jar file show in eclipse when I hover over a class.
For example, after downloading JODA-2.0, three jars are
The easiest way is :
jdk
.Than select
src
.zip.The Problem is Solved.
You can try to CTRL + click on a class that has no source attached (do that in editor). When it shows you some info about the class you'll see the button that guides to attach source dialog. Click it and in dialog that pops up pick the source/javadoc location for your class.
You can also do that from project build path settings you are mentioning: pick libraries tab, expand the library (jar) you want and you'll be offered to pick: source attachment, javadoc attachment, native library location, etc. You just pick whatever you want and edit its current settings.
Or you can do as @JB Nizet said...
Right-click on the jar (the one with the class files), choose "Properties", the "Javadoc location", and choose the jar file with the javadoc. Do similarly for the source jar, using "Java source attachment".
You can also edit the classpathentry in the file ".classpath" in your eclipse project. This can be helpful if you want to modify many entries at once or if you want to generate the path. e.g.:
<classpathentry kind="var" path="HOME/3rdparty/junit.jar" sourcepath="/SOURCE/junit_src.zip"/>